<!DOCTYPE html>
<html lang="en">

  <head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, initial-scale=1.0">
    <title>原生popup弹出层</title>
    <style>
      #event-popup {
        width: 600px;
        height: 400px;
        border: 1px solid lightgreen;
        border-radius: 20px;
        padding: 10px;
      }
    </style>
  </head>

  <body>
    <div id="event-popup"
         popover>
      oahahaha
    </div>

    <button popovertarget="event-popup">
      Create New Event
    </button>
  </body>

</html>
